A new strain of Cordyceps javanica (wf GA17) was observed causing widespread epizootics among whiteflies in Southern Georgia in 2017. The tolerance of conidia to environmental factors including variable temperature and ultraviolet (UV) light was compared between this strain and three commercial strains of entomopathogenic fungi (Metarhizium brunneum F52, Cordyceps fumosorosea Apopka97, and Beauveria bassiana GHA). Under 10–30 °C, C. javanica wf GA17 responded similarly to other fungi, with the highest virulence against Galleria mellonella at 25 °C, followed by 20, 30, and 15 °C; lowest virulence was observed at 10 °C. At 35 °C and 40 °C, C. javanica wf GA17 had lower tolerance than M. brunneum F52 and B. bassiana GHA, but was superior to C. fumosorosea Apopka97 in conidia viability and post-treatment virulence. After exposure to −20 °C for 56 d, C. javanica wf GA17 exhibited lower germination than M. brunneum F52 and lower virulence than M. brunneum F52 and B. bassiana GHA, but higher germination and virulence than C. fumosorosea Apopka97. Following exposure to strong UV light, viability and virulence of all fungi were reduced with increasing exposure periods. Increased environmental tolerance of C. javanica wf GA17 over C. fumosorosea Apopka97 suggests that the new strain could have applicability for commercial pest management.

中文翻译：

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病原性真菌的环境耐受性：从粉虱流行与商业真菌菌株分离的虫草新菌株。

2017年，观察到一株新的虫草冬虫夏草（wf GA17）在乔治亚州南部的粉虱中引起广泛的流行病。比较了该菌株与三株商业致病性菌株对分生孢子的耐受性，包括可变温度和紫外线（UV）真菌（绿僵brunneum F52，虫草fumosorosea Apopka97，和白僵菌GHA）。下10-30℃，C.鸦胆子WF GA17的反应相似于其它真菌，与针对最高毒力大蜡螟，在25℃，随后20，30，和15℃; 在10°C时观察到最低的毒性。在35°C和40°C下，C. javanicaWF GA17具有比较低的公差M. brunneum F52和球孢白僵菌GHA，但优于C. fumosorosea在分生孢子存活和后处理的毒力Apopka97。暴露于-20℃，56 d后，C.鸦胆子WF GA17表现出低于发芽M. brunneum F52和毒力比低M. brunneum F52和球孢白僵菌GHA，但高于发芽和毒力C. fumosorosea Apopka97。暴露于强紫外线后，所有真菌的生存力和致病力随着暴露时间的延长而降低。C. javanica wf GA17比C. fumosorosea提高的环境耐受性 Apopka97表明，该新菌株可用于商业有害生物管理。